Calculator.



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CALCULATOR.

(Apgliution Mod Doc. 20, 1897. )would June 7, 1900.) (lo Model.) 2Sheets-Shut l.

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No. 666,091. Patented 1an. L5, 190|.

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UNITED STATES VPATENT OFFICE.

FREDERICK DUNCAN FERGUSSON, OF PAEROA, NEW ZEALAND.

CALCULATOR.

SPECIFICATION forming part of Letters Patent N o. 666,091, dated January15, 1901.

Application filed December 29, 1897. Renewed June '7, 1900. Serial No.19,491. (No modeLl To all whom it may concern:

Be it known that I, FREDERICK DUNCAN FERGUSSON, a subject of the Queenof Great Britain, residing at Paeroa, Auckland, New

Zealand, have invented a new and Improved Calculator, of which thefollowing is a full, clear, and exact description.

The object of the invention is to provide a new and improved calculatorwhich is simpleand durable in construction, easily manipulated, and moreespecially designed for quickly and conveniently calculating timber,earth quantities, interest, dac.

The invention consists, principally, of carriers or blocks movable inparallel guideways, a connection between the two blocks, and a scale orscales between the said guideways and on which reads the connection.

The invention also consists of certain parts and details andcombinations of the same, as will be fully described hereinafter andthen pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar characters of reference indicatecorresponding parts in all the figures. Y

Figure l is a plan View of the improvement. Fig. 2 is a sectional sideelevation of the same, and Fig. 3 is a face view of a table used inconnection with the device.

The improved calculator is preferably mounted on a suitablyeconstructedboard or table A, formed on its face with parallel guideways B and C,placed a suitable distance apart to leave a space A between the saidguideways, and a second space A2 adjacent to the guideway C on the topof the table or board A. The space A is used for scales or graduationsR2 and S2, and the space A2 is formed with a scale or graduation L,indicating linear measurement.

On the sides of the guideway B are arranged scales or graduations S andRl, and on one side of the guideway C is arranged a graduation Q.

In the guideways B and C are fitted to slide the carriers or blocks Dand E, respectively, of which the carrier D is provided with pointers DD2 for indicating on the graduations S and R', respectively, and asimilar pointer E is on the carrier E for indicating on the graduationQ.

On the top of the carrier D is arranged a pin D3, engaged by a loop onone end of a string or cord F, extending across the space A to passloosely through an eye E2, formed on the carrier E, the cord thenextending,with the portion F, over the space A2 to finally pass throughan aperture in a guide-plate G and through the wall of the table to theoutside thereof to carry at this end a weight F2 for holding the cord orstring taut on the top of the table.

A graduated bar H, containing the result sought, has its ends fitted toslide iu suitable guideways I, arranged on the table A. This bar movesalong the graduation L, and its left-hand edge (see Fig. 1) indicatesthereon. A graduation X on said bar is read by the part F on the cord Fas the latter extends over the space A2. y

Now it is evident that the carriers D and E when shifted in theirrespective guideways shift the cord F accordingly, so that the said cordindicates ou diiferent points on the graduations S2, R2, and X. Now thegraduation L,with the movable bar H and the graduation X, constitutes aproportion-scale in the form of a right-angled triangle, of which theaperture in the plate Gis the apex and the guideway C, the part F' ofthe cord F the hypotenuse, and a line extending through the aperl ure inthe plate Gand parallel to the side of the table the altitude. Theaperture in'plate G, Zero on the scale X, and the maximumreadings-namely, 12 and 17 on scales S and R-must be in the samestraight line. The graduation S2 is along a line indicated by the cord Fwhen the block D' stands at zero on scale S', with the carrier E placedso that the part F of the cord F intersects zero on scale X. Thegraduations R and R2 are specially formed for calculating quantities ofearthwork, as in road or railway cuttings.

Now in order to use the device, say, for instance, for 'finding thenumber of superficial feet in any number of similar boards, the length,width, and thickness of one board being given, the operatorrst lindsfrom the table shown in Fig. 3 the number of running IOO feet and thenmoves the bar H along its guideways I until the graduated edge of thesaid bar indicates on the graduation L the number derived from the saidtable. (Shown in Fig. 3.) The operator now moves the carrier D until thepointer D indicates the width of the board in inches on the scale S',and then the operator moves the other carrier E until the cord F crossesthe graduation or scale S2 at the point indicating the thickness of theboard in inches. The result is now read by the string -or cord part F onthe graduation X at the intersection of the said cord with thegraduation. The scale X must be read the same as the scale or graduationL, For example, if the bar H indicates at 18.70" on the graduation L tostand for eighteen hundred and seventy running feet then the cordcrossing the scale X at 45.402 means four thousand ve hundred and fortysuperiicial feet.

When it is desired to find the actual number of superficial feet in around log, the circumference of which is given, then the operatorproceeds as follows: The bar H is set on the graduation or scale L tothe length of the log in feet, the said scale being read as units. Thecarrier D is then adjusted in the guideway B until the pointer D2indicates on the graduation R the circumference of the large end of thelog in feet and inches, and then the other carrier E is adjusted untilthe cord F crosses the scale R2 at the point indicating thecircumference of the small end of the log, likewise in feet and inches.The result is read at the intersection of the cord on the graduation Xof the bar H as the said cord crosses the bar H at the required numberof superficial feet.

To nd the actual number of cubic feet in a round log when thecircumference of each end is known, then the operator iirst proceeds asabove described in reference to Finding the number of superficial feet,and then the result is divided by twelve.

IVhen it is desired to find the number of superficial feet that can besawed or cut from a round log after allowing for waste in slabs, te.,during the cutting, the operator first sets the bar H to the length ofthe log in feet on the scale L, reading the latter as units, and thenmoves the other carrier E to indicate with its pointer the meancircumference in feet and inches of the log on the scale Q. The resultis now read on the graduation X at the intersection of the cord F on thesaid scale. Divisions l2 and 17 on the guideway B, zero on scale X, andthe aperture in guideplate G must be in one and the same straight lineto form one side of a triangle having as the hypotenuse the cord F. Inthe arrangement shown I took twenty-four feet as a convenient maximumlength for scale L, twelve inches as a convenient maximum length forscale S, and six inches as a convenient maximum length for scale S2.This gives as a result one hundred and forty-four superficial feet asmaximum result. Scale X, scales S' and X were then arbitrarily fixed andevenly divided, occupying the width of the board or table. I then made atable of results showing the number of superiicial feet in a boardtwenty-four feet long which was twelve by one, twelve by two, twelve bythree, dac., eleven by one, eleven by two, tc., and so on. I then set Hat 24 on scale L. Now take an example: To find the position of division2 on scale S2, a twenty-four-foot board twelve by two containsforty-eight superficial feet, a twenty-four-foot board eight by twocontains thirty-two superficial feet. Set the bar H at 24 on the scale Land set the carrier D at I2 on the scale S. Now move the other carrier Euntil the thread or cord F crosses the result forty-eight on the scale Xand draw a line across Athe space A', marking the position of the cordor thread. rIhen set the carrier D at S on the scale S and move thecarrier E until the cord or thread crosses the result thirty-two onscale X and draw another line as before. The intersection of these lineswill give the position of 2 on scale S2, and so on. The subdivisions maybe found this way or by geometrical construction. Scales R and R2 aresimilarly found.

It is evident that from the foregoing the device can be readily used forvariousv other purposes besides the ones mentioned, and it is furtherevident that additional and different scales may be employed for certaincalculations,the said scales being located,however, in the space betweenthe guideways B and C and with a proportion-scale adjacent to theguideway C.

Having thus fully described my invention, I claim as new and desire tosecure by Letters Patent* I. A calculator, provided with carriersmovable in parallel guideways, scales disposed along said guideways andon which scales the carriers read, a connection between the twocarriers, a scale or scales between the said guideways, the connectionbeing movable over the scale or scales to indicate thereon, and aproportion-scale adjacent to one of the guideways, and on whichindicates an extension of the said connection, substantially as shownand described.

2. A calculator comprising a table formed with parallel guideways,carriers fitted to slide in the said guideways, scales disposed alongsaid guideways and on which scales the carriers read, additional scalesarranged on the table between the said guideways, a ilexible connectionbetween the said carriers, a proportion-scale arranged at one side ofthe carrier, and formed by a fixed scale indicating linear measurement,a movable bar having a resultant graduation, and a connection extendingfrom one of the said carriers over the said proportion-scale, forindicating on the bar, substantially as shown and described.

IOO

IIO

3. A calculator, provided with a table, two spect to the last-namedscale and the flexible carriers movable thereomascale or scales onconnection reading on the bar and on the lo the table and situatedbetween the carriers, said scale or scales which are located between ailexible connection extending between the the carriers.

5 carriers and engaged at one end with the ta FREDERICK DUNCANFERGUSSON.

ble, a bar with a scale thereon, and a scale Witnesses: formed on thetable adjacent to the bar, the J. P. MEAGHER,

bar being adjustable on the table with re- J. M. WEAGLE.

